planting a new garden.
Before starting an agriculture work or buying land an important thing to do is conduct a soil test. I will explain how to conduct this test below.
Soil test will provide to a large extent composition of the soil, pH of the soil which tells if the soil is acidic (below 7) or alkaline (above 7) or neutral (7). Generally soils of 5-6.6 is considered as suitable for most crops, pulses and vegetables and for gardens. Some crops and vegetables are very sensitive to low or high soil pH and therefore will not grow under these conditions to the best production potential. Some crops will not germinate if the pH is below 4.8. The image below shows which level of pH is required for some crops.
Using lime at a suitable rate can help but if the pH is very low (below 4.7) then it is very difficult to correct the soil pH with lime in a short time.
Soil test will also provide the information regarding if the soil has too much of Nitrogen ( from either urea or NPK), Phosphorus and Potassium. Very high levels of nitrogen generally results in farmer using excessive nitrogen from fertilizers thinking it will increase production. However high levels of nitrogen can result in making some crops less productive due to diseases. Deficiency of some trace elements such as molybdenum also can cause growth reduction.
High levels of nitrogen also results in being carried by water (run off) when there is high rainfall and this will go and flow into the rivers and creeks. This will cause weeds, algae (toxic) and bacteria (toxic) to grow near the river beds and in the water. This water will enter the water table and run into the water humans drink. When humans and cattle or sheep drink this water it will cause diseases in humans and animals. This will also waste nitrogen as studies have shown that about 40% of nitrogen runs off in water.
Soil needs to have optimum pH, Nitrogen (N), Phosphorus (P), Potassium, Iron (Fe), Molybdenum (Mo), Zinc (Zn), Manganese (Mn), Magnesium (mg) and Copper (Cu) at the least.
Soil pH also has another impact. Low pH can result in having high toxic levels of Aluminium (Al) and or high levels of Manganese (Mn). Both the toxic elements result in growth reduction and growth suppression. This condition is called as acidic soil.
High pH can also be associated with high levels of salt in the soil. This condition is called as soil salinity. Both these toxic conditions are due to excessive use of fertilizers without testing the soil. Both these conditions can become permanent if it is left without corrections. Therefore the land becomes barren and degraded.
How to conduct soil test
It is very simple to collect and send the soil samples for testing.
you will need
2 large bags (plastic)
1 small digger or a shovel
1 Pen and labels ( paper)
Land for testing
1. Choose a day after the rain fall and rain has dried to a large extent but moisture is still there in the soil.
2. Use the shovel or the digger to dig the soil for about 10 cms ( length of your hand)
3. Dig out some small amount of soil and place it in the plastic bag 1.
4. Dig in 10 random spots across the land where a crop or a garden will grow.
5. Place the dug out soil from each of the 10 spots in the plastic bag 1.
6.Now mix up the soil carefully and throughly with hand.
7. Place the required amount ( as required by the testing company) of the mixed soil in the bag numbered 2.
8. Send the mixed soil to the soil testing company.
9. When the results are provided take it to the local agricultural officer for assessment and correction recommendation.
10. Use the right type of fertilizer to correct the soil.
Note: In most of the western countries soil testing kits are available to test pH only. testing for pH only may not be enough for best production.
Test the soil once in 2-3 years to make sure you have done the correction for that specific crop you want to grow.
testing the soil and correcting excessive elements and deficiencies will give best possible yield for the year.
when sending the soil for testing make sure you ask for the NPK and the elements mentioned above (Mg, Mn, Zn, Fe, Cu Mo) to be tested. Ask for pH to be tested. Ask them to test for Aluminium and Manganese saturation percentages. These will give the percentage of these elements available to the plants when growing in the soil. If Aluminium is above 6% you will need to add several tonnes of line to correct the pH. However not all the low pH soils will have Aluminium and Manganese toxicities.
Soil testing center information for Karnataka found on the web sites.
(The author has no knowledge of how good these centers are)
2K Plus Geotechnique (Soil Testing - Bangalore)
Contact: 2944, V Ngr-560040. Phone: 080-23300645
Anantha Consultants (Soil Testing - Bangalore)
Contact: Mr. Sheshu
385/11, 1st N Blk R-Ngr-560010. Phone: 080-23326988
Aptech Foundations (Soil Testing - Bangalore)
Contact: Mr Venkatesh
1380 Sri Venkatadri I Flr Off 6th Crs Ashok Ngr Bsk I Stg-560050. Phone: 080-26672868
Deccan Engineers (India) (Soil Testing - Bangalore)
Contact: Mr. Bhaskar
No.30 Attur Layout Ambabhavani Temple Rd Yelahanka-560064. Phone: 080-28563487
Geo Engineering Co Pvt Ltd (Soil Testing - Bangalore)
Contact: 12 Palace Rd-560052. Phone: 080-22265498
Karnataka Test House Pvt. Ltd. (Soil Testing - Bangalore)
Contact: Mr. K.B.V. Pathi
8th Cross Triveni Rd Ypr-560054. Phone: 080-23378383
Nagadi Consultants (Soil Testing - Bangalore)
Contact: 1014 1st Mn 4th Blk R Ngr-560010. Phone: 080-23356076
Optimum Use Material Centre (Soil Testing - Bangalore)
Contact: Mr. Venkatesh
1380, Sri Venkatadri,Off 6th Crs,Ashok Ngr Bsk I Stg-560050. Phone: 080-26672819
Struct Geotech Research Laboratories Private Limited (Soil Testing - Bangalore)
Contact: Mr. Manoj
588, 6th Blk Hoskerehalli Crs Bsk 3rd Stg 2nd Ph-560085. Phone: 080-26422752
Vel Engineering Consultants (P) Ltd (Soil Testing - Bangalore)
19, 3rd Mn Rd Extn,Venkateswara Ngr,Velachery CHN-600042. Phone: 044-22591667
This information is provided for education of people. The author has no affiliation with any of the testing centers or University of Agriculture in any way. Please telephone first and ask for information and get the tests conducted. Consult an agricultural officer to take corrective actions.